MXS-2243_labels Maxscale system tests prepare environment by themselves

maxscale-system-test changed in order to control test environment by itself.
Every test checks which machines are running, compare with list of needed machines
and start new VMs is they are missing in the running machines list.
Tests are executiong MDBCI commands, MDBCI executable should be in the PATH

maxscale-system-test/test_ctrl_c/start_killer.sh

@@ -1,3 +1,3 @@
 sleep 5
-$maxscale_access_sudo /usr/bin/killall maxscale -s INT
+sudo /usr/bin/killall maxscale -s INT
 

maxscale-system-test/test_ctrl_c/test_ctrl_c.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-$maxscale_access_sudo service maxscale stop
+sudo service maxscale stop
 
 hm=`pwd`
 $hm/start_killer.sh &
@@ -10,7 +10,7 @@ fi
 
 T="$(date +%s)"
 
-$maxscale_access_sudo maxscale -d -U root
+sudo maxscale -d -U root
 if [ $? -ne 0 ] ; then
 	exit 1
 fi